WASHINGTON -LRB- CNN -RRB- -- President Bush 's top adviser on homeland security is stepping down after 4 1/2 years on the job , the White House said Monday .

Fran Townsend served more than four years as homeland security adviser .

Homeland Security Adviser Fran Townsend turned in her letter of resignation to President Bush on November 6 and will be looking for new opportunities outside government .

`` I 'm going to just take another job doing 20-hour days , but this time in the private sector , '' said Townsend , who has spent 25 years working in law enforcement and government .

Bush praised Townsend 's work Monday .

`` Fran has always provided wise counsel on how to best protect the American people from the threat of terrorism , '' Bush said in a statement . `` We are safer today because of her leadership . ''

Townsend 's job , as the president 's top adviser on fighting terrorism , involved identifying terrorist groups around the globe and assessing their threat , and finding ways to track and cut off their funding . She said that experience should will be useful in the private sector as well .

Townsend -- the mother of two , ages 6 and 12 -- said she first will look into public speaking , writing and board work before pursuing opportunities in global risk management for a large multinational corporation or financial institution . Watch how Townsend is planning to use her skills ''

She said she 's been talking with the president about her planned departure for eight months .

Townsend 's name had come up during the president 's recent search for a new attorney general , but she was not considered . She said not getting the job `` had absolutely nothing to do with her decision to leave . ''

She said Bush had wanted her to stay on in his administration .

`` It was a hard decision as I have loved and will cherish my every minute of service , '' she said in an e-mail . `` My family actually advocated that I remain and has always been supportive of my service so this was entirely my decision . ''

Townsend is part of the search committee to find a replacement by the beginning of next year . The president appoints the senior staff position , and it needs no Senate confirmation . E-mail to a friend

CNN 's Suzanne Malveaux contributed to this report .

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Fran Townsend says she 'll look for opportunities in the private sector

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Townsend has worked in government and law enforcement for 25 years

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Townsend will be on a panel searching for a replacement